We assume that the holes and electrons generated in the i-regions due to the ZK interband tunneling propagate ballistically or near ballistically [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}.
Due to the specific of the ZK interband tunneling in GLs [8]}, the velocity, \(v = \pm v_W\) , of the generated electrons and holes is directed primarily along the electric field in the
i-region, i.e., in the \(x-\)  direction.
If the i-region length \(2l \lesssim 1~\mu \) m, the transport of the injected holes and electrons in the i-region
can be ballistic
at room and lower temperatures [7]}, [10]}.
In this case, the average electron and hole velocities across the entire i-region
are equal to \(\pm v_W\) , where \(v_W \simeq 10^8\)  cm/s is the characteristic carrier velocity in GLs.
